Could a skin odor test result in early diagnosis of Parkinson’s disease?

Researchers from the University of Manchester (UK) have discovered small molecules in sebum secreted by the skin that are responsible for a unique scent in individuals with Parkinson’s. This discovery could lead to the development of a much needed, early diagnosis test for the neurodegenerative condition resulting in treatment programs being initiated at an earlier stage.

There is currently no definitive diagnostic test available for the neurodegenerative disorder, however, it is already known that Parkinson’s can cause excessive production of sebum, a lipid-based fluid that moisturises and protects the skin. Joy Milne, Honorary Lecturer at The University of Manchester, also observed that individuals with Parkinson’s possessed a unique smell which she first noticed in her husband Les many years prior to his clinical diagnosis. This smell is distinct and different from people without Parkinson’s, and changes intensity as the condition progresses meaning it could be used to detect and monitor the condition.

In the study, published in the journal ACS Central Science, sebum samples were collected from the upper backs of more than 60 individuals, both with and without Parkinson’s, before mass spectrometry was used to identify the molecular compounds responsible for the unique odor associated with the condition.

The volatile components from the sebum of people diagnosed with Parkinson’s were analyzed at a molecular level, and it was discovered that hippuric acid, eicosane and octadecanal were present in all samples, indicating the altered levels of neurotransmitters as well as several other biomarkers for the condition.

By considering the levels of these molecules found in the test samples, the team has generated a model that can now identify and diagnose Parkinson’s at all stages of the condition.

“Now we have proved the molecular basis for the unique odour associated with Parkinson’s we want to develop this into a test,” explained Perdita Barran, Professor of mass spectrometry at the University’s Manchester Institute of Biotechnology (UK). “This could have a huge impact not only for earlier and conclusive diagnosis but also help patients monitor the effect of therapy. We hope to apply this to at risk patient groups to see if we can diagnose, pre-motor symptoms, and assist with potential early treatment.”

David Dexter, Deputy Director of Research at Parkinson’s UK, added: “Finding changes in the oils of the skin in Parkinson’s is an exciting discovery that was sparked by a simple conversation between a member of the public and a researcher.”

“More research is needed to find out at what stage a skin test could detect Parkinson’s, or whether it is also occurs in other Parkinson’s related disorders, but the results so far hold real potential. Both to change the way we diagnose the condition and it may even help in the development of new and better treatments for the 145,00 people living with Parkinson’s in the UK.”

Consultant Neurologist and Senior Lecturer at The University Manchester, Monty Silverdale, concluded: “We acknowledge this is a small study but it does open the door to the development of a non-invasive screening test for Parkinson’s, potentially leading to earlier detection for thousands of patients.”